This isn't the first time the world has been engaged in a conversation about "vaccine passports." And there even is a version of a passport currently in use – the World Health Organization-approved yellow card, which since 1969 has been a document for travelers to certain countries to show proof of vaccination for yellow fever and other shots. Without which they can't visit those countries.
But first, let's flash back to the late 19th century – 1897 to be exact. A scientist from Odessa, Russia, Waldemar Haffkine, developed a vaccine for plague. He was hailed as the "Jewish Jenner" (a shout-out to Edward Jenner, inventor of the smallpox vaccine in 1796).
Once Haffkine's vaccine was put into use in British India, discussions started about asking for proof of vaccination in certain circumstances, according to Sanjoy Bhattacharya, a professor of history at the University of York in the U.K. and director of the WHO Collaborating Center for Global Heath Histories.
One area of concern: Hindu and Muslim pilgrimage sites, which, due to population density, were considered spaces where outbreaks of plague could get out of control.
A good example, says Bhattacharya, was the annual pilgrimage to the town of Pandharpur in the colonial Bombay province. Authorities decided to make proof of vaccination compulsory for pilgrims but only after detailed, annual negotiations between government, the railway companies, the hospitality industry, pilgrims' representative and temple authorities.
Bhattacharya stresses that no world body can order such a requirement. It can only come about as the end result of long deliberations among relevant parties, he says.
Similar discussions were held about smallpox at about the same time at the plague vaccine was developed. "When there were outbreaks in South Asia people from there were not allowed to board ships, for instance, to Aden or Great Britain, or Mecca for the Hajj, without government-issued smallpox vaccination certificates," Bhattacharya says. At that time, vaccinations were given at government centers, which handed out a certificate to those who got the vaccine.
"These matters were considered even more urgent in the second half of the 20th century after the introduction of air travel," says Bhattacharya. In that era, someone infected with smallpox could quickly and easily reach Europe while infected and cause local outbreaks of this much-feared disease. So, smallpox vaccination certification checks were enforced before travel, "with forcible isolation at airports of any passengers considered to have dubious documentation."
Vaccine certification checks came under the International Sanitary Regulations adopted in 1951 by WHO member states (and replaced by and renamed the International Health Regulations in 1969.
Currently, yellow fever is the only disease specified in the International Health Regulations for which countries may require proof of vaccination as a condition of entry. However, WHO can recommend, based on outbreaks, that countries ask for other vaccines. For example, there is a current recommendation that Pakistan and Afghanistan ask travelers to be vaccinated with a single adult dose of polio vaccine if they have not been vaccinated against polio since childhood.
But any type of vaccine proof is not a blanket rule all must follow, says Bhattacharya. "All recommendations from WHO are necessarily advisory in nature and open to interpretation across countries, during implementation."
So that's one of several concerns about any effort to create a global COVID-19 passport.
"No entity has a mandate to create universal certification, and the situation is tricky because it could be at least a couple of years before everyone in the world is vaccinated," says Jen Kates, senior vice president and director of Global Health & HIV Policy at the Kaiser Family Foundation in Washington, D.C. "A certification now could exacerbate inequities for such things as employment in other countries for people not yet vaccinated," says Kates.
In February, WHO published a position paper on the scientific, ethical, legal and technological issues that may arise when requiring international travelers provide proof of a COVID-19 vaccination. The paper recommended against requirements of proof. WHO reiterated that position to NPR this week again for several reasons. To quote their email:
"At the present time, it is WHO's position that national authorities and travel operators should not introduce requirements of proof of COVID-19 vaccination for international travel as a condition for departure or entry for a number of reasons.
"The efficacy of vaccines in preventing transmission is not yet clear, and the current limited global vaccine supply. While many vaccines have been shown to protect against disease, studies are ongoing to determine if they also stop the transmission of the virus: that a person who is vaccinated cannot carry the virus and give it to others.
"WHO recommends that people who are vaccinated should continue to comply with other risk-reduction measures when traveling."
That's not WHO's final word on vaccine certificates. The agency says, "our recommendations will evolve as supply expands and as evidence about existing and new COVID-19 vaccines is compiled."
But WHO may not have the luxury of time. "This train [of vaccine certification] has already left the station because people want to know that the people around them are immunized," says Dr. Chris Beyrer, the Desmond M. Tutu Professor of Public Health and Human Rights at the Johns Hopkins Bloomberg School of Public Health. The European Union, for example has proposed what it's calling a digital green pass that could allow travel for people who've been vaccinated, recovered from COVID-19 or show a negative test for the virus.
Like Kates, Beyrer says he understands WHO's position because there are still countries "who have yet to administer a single dose." And in this have- and have-not situation, people without certificates likely wouldn't be able to go to school or look for work in other countries.
Meanwhile, the goal of vaccine equity across the globe isn't just for economic or educational reasons, Beyrer points out. "Leave swaths of people unimmunized, and we run the risk of more of these variants of concern and an undermining of the current generation of vaccines."
As for what the certification will look like, Beyrer is sentimental about his own yellow card from his work in the 1990s in polio eradication and measles control in Caribbean countries. But he predicts the era of paper proof is coming to an end. He thinks any certificate for COVID-19 will be a smart app linked to a central database or electronic health records.
"Of course," says Beyrer, "that raises the issue of the digital divide in many countries."
The U.S. at least for now is content with issuing the same kind of proof of vaccination as from the era of the plague vaccine: a paper certificate with the vaccine information added in ink.
Fran Kritz is a health policy reporter based in Washington, D.C., who has contributed to The Washington Post and Kaiser Health News. Find her on Twitter: @fkritz
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